Harris is out on a $15,000 bond.
Peacock was shot while sitting in his personal vehicle close to the Rosedale Courthouse.
"Harris walked up to the victim, said something, pulled his weapon and shot him in the left bicep area," said Bolivar County Sheriff Kelvin Williams. "The victim then drove himself to the courthouse."
Peacock was transported to the Bolivar Medical Center and later to the Delta Regional Medical Center in Greenville.
"Sometime during the night Harris turned himself in to the Bolivar County Sheriff's Department," added Williams. "He was then processed and booked by the Rosedale Police Department."